Surface cleaning apparatus with dirt arrester having an axial step

ABSTRACT

A surface cleaning apparatus has a cyclone chamber having a longitudinal cyclone axis of rotation wherein the dirt outlet is defined by a gap between the sidewall of the cyclone and a plate positioned at the dirt outlet end of the cyclone, which gap extends around all of the perimeter of the plate. The plate is stepped in the axial direction.

FIELD

This disclosure relates generally to surface cleaning apparatus. In apreferred embodiment, the surface cleaning apparatus comprises acyclonic separator including a plate (also referred to as an arresterplate) at the dirt outlet and of a cyclone chamber wherein the plate hasan axial step.

INTRODUCTION

The following is not an admission that anything discussed below is partof the prior art or part of the common general knowledge of a personskilled in the art.

Various types of surface cleaning apparatus are known. Such surfacecleaning apparatus include vacuum cleaners, including upright vacuumcleaners, hand carriable vacuum cleaners, canister-type vacuum cleanersand Shop-Vac™ type vacuum cleaners. Some vacuum cleaners include acyclonic separator (also referred to as a cyclone bin assembly) having acyclone chamber, a dirt collection chamber, and a plate at the dirtoutlet end. See for example Conrad (U.S. Pat. No. 8,640,304).

SUMMARY

This summary is intended to introduce the reader to the more detaileddescription that follows and not to limit or define any claimed or asyet unclaimed invention. One or more inventions may reside in anycombination or sub-combination of the elements or process stepsdisclosed in any part of this document including its claims and figures.

According to a first aspect of this disclosure, which may be used byitself or in combination with one or more other aspects of thisdisclosure, a cyclone is provided at the dirt outlet end of the cyclonechamber with a plate that is stepped in the axial direction. The dirtoutlet is defined at least in part by a gap between the plate and thesidewall of the cyclone chamber. Stepping the plate in the axialdirection enables a portion of the plate to define a larger dirt outletso as to enable larger dirt to exit the cyclone chamber.

In accordance with this aspect, there is provided a surface cleaningapparatus comprising:

(a) an air flow path extending from a dirty air inlet to a clean airoutlet;

(b) a cyclone and a suction motor provided in the air flow path;

(c) the cyclone comprising a cyclone chamber having a centrallongitudinal axis, the cyclone having a first end having a first endwall, an axially spaced apart second end, a cyclone chamber sidewalllocated between the first and second ends, a cyclone air inlet providedat the first end, a cyclone air outlet provided at the first end and adirt outlet provided at the second end, wherein a reference plane thatis perpendicular to the central longitudinal axis extends through thecyclone chamber; and,

(d) a plate located at the second end, the plate having a plateperimeter, a first portion,

-   -   (i) a second portion and a transition portion provided between        the first and second portions, each of the first, second and        transition portions of the plate having a cyclone chamber face        wherein the cyclone chamber faces of the first and second        portions of the plate face towards the first end and border        different portions of the plate perimeter,    -   (ii) the second portion is spaced in a direction parallel to the        central longitudinal axis further from the reference plane than        the first portion,    -   (iii) the dirt outlet comprises a spacing between the cyclone        chamber sidewall and the second portion of the plate,    -   (iv) the plate also having a dirt chamber face and a step        volume, the step volume positioned axially between the cyclone        chamber faces of the first and transition portions and the dirt        chamber face whereby the dirt chamber face comprises a closure        portion which underlies the step volume; and,

(e) a dirt collection region in communication with the cyclone chambervia the dirt outlet.

In any embodiment, the closure portion may extend at an angle to thecentral longitudinal axis.

In any embodiment, the first portion of the plate may be thicker thanthe second portion of the plate.

In any embodiment, a thickness of the first portion of the plate mayincrease towards the transition portion of the plate.

In any embodiment, a first discontinuity may be provided between thecyclone chamber face of the first portion of the plate and the cyclonechamber face of the transition portion and a second discontinuity may beprovided between the cyclone chamber face of the transition portion andthe cyclone chamber face of the second portion of the plate.

In any embodiment, the transition portion may extend generally axially.

In any embodiment, the first portion of the plate and the second portionof the plate may be generally planar.

In any embodiment, the dirt chamber face of the plate may be generallycontinuous.

In any embodiment, the dirt collection region may be axially spaced fromand opposed to the first end of the cyclone.

In any embodiment, the closure portion may be planar.

In any embodiment, the closure portion may extend from a first endproximate a dirt chamber face of the second portion towards or acrossthe central longitudinal axis to a second end, and the first end of theclosure portion may be laterally spaced from the second end of theclosure portion.

In accordance with this aspect, there is also provided a surfacecleaning apparatus comprising:

(a) an air flow path extending from a dirty air inlet to a clean airoutlet and including a cyclone chamber and a suction motor;

(b) a dirt collection region external to the cyclone chamber; and,

(c) a plate positioned between the cyclone chamber and the dirtcollection region and defining a dirt outlet from the cyclone chamber tothe dirt collection region, the plate having a cyclone chamber facefacing the cyclone chamber, an opposed dirt collection face facing thedirt collection region, and first, second, and transition portions,wherein cyclone chamber faces of the first and second portions areconnected by a cyclone chamber face of the transition portion and aredifferent axial distances from a transverse plane that extends throughthe cyclone and that is perpendicular to a central longitudinal axis ofthe cyclone, and the dirt collection face closes a step volume borderedby the first and transition portions.

In any embodiment, the first portion of the plate may be thicker thanthe second portion of the plate.

In any embodiment, the dirt chamber face of the plate may be generallycontinuous.

In any embodiment, the dirt collection region may be axially spaced fromand opposed to the first end of the cyclone.

In any embodiment, a first discontinuity may be provided between thecyclone chamber face of the first portion of the plate and the cyclonechamber face of the second portion of the plate.

In any embodiment, the first portion of the plate and the second portionof the plate maybe generally planar.

In any embodiment, the closure portion may extend at an angle to thecentral longitudinal axis.

In any embodiment, the closure portion may be planar.

In any embodiment, the closure portion may extend from a first endproximate a dirt chamber face of the second portion towards or acrossthe central longitudinal axis to a second end, and the first end of theclosure portion may be laterally spaced from the second end of theclosure portion.

In accordance with another aspect, there is provided surface cleaningapparatus comprising:

(a) an air flow path extending from a dirty air inlet to a clean airoutlet

(b) a cyclone provided in the air flow path, the cyclone comprising acyclone chamber, a cyclone air inlet, a cyclone air outlet, a dirtoutlet, a central longitudinally extending axis, the cyclone chamberhaving first and second axially opposed ends;

(c) a suction motor positioned in the air flow path;

(d) a dirt collection region external to the cyclone chamber; and,

(e) a plate positioned at the second end of the cyclone chamber, theplate having a cyclone chamber face facing the cyclone chamber, thecyclone chamber face having first and second portions, wherein the firstportion of the cyclone chamber face and the second portion of thecyclone chamber face are different axial distances from a transversereference plane that extends through the cyclone chamber and that isperpendicular to the central longitudinally extending axis of thecyclone, wherein an annular gap between the plate and the cycloneextends around all of the plate and defines the dirt outlet of thecyclone chamber.

In any embodiment, the annular gap may have a radial distance betweenthe plate and the cyclone and the radial distance may be constant.

In any embodiment, the annular gap may have a radial distance betweenthe plate and the cyclone and the radial distance may vary at differentlocations around the plate.

In any embodiment, the plate may have a perimeter and the perimeter mayextend generally continuously.

In any embodiment, the plate has a perimeter and the perimeter has twodiscontinuities.

In any embodiment, the plate may have a segment removed. Optionally, theannular gap may have a radial distance between the plate and thecyclone, the radial distance may vary at different locations around theplate and the radial distance may be increased at a location of theplate from which the segment has been removed. Alternately, or inaddition, the second portion may be a greater axial distance from thetransverse plane than the first portion and the location of the platefrom which the segment has been removed may be the second portion.

In any embodiment, the second portion may be a greater axial distancefrom the transverse plane than the first portion and the second portionhas a segment removed. Optionally, the annular gap may have a radialdistance between the plate and the cyclone and the radial distance maybe increased at a location of removal of the segment.

In any embodiment, the plate may be positioned between the cyclonechamber and the dirt collection region, the plate may have a dirtcollection face facing the dirt collection region.

In any embodiment, the cyclone air inlet and the cyclone air outlet maybe provided at the first end of the cyclone chamber, the cyclone airoutlet may comprise a vortex finder and porous member positioned betweenthe cyclone chamber and an inlet of the vortex finder, and the vortexfinder and porous member may be spaced from the cyclone chamber face ofthe plate.

In any embodiment, the plate may be moveably mounted between a closedposition, in which the plate is positioned for operation of the cycloneand an open position wherein the plate is moved to provide access to thecyclone chamber.

In any embodiment, the dirt collection region has an end wall facing theplate and the end wall may be openable. Optionally, the plate may besupported by the end wall and is moveable with the end wall.

In any embodiment, the plate has a dirt collection face facing the dirtcollection region and the surface cleaning apparatus may furthercomprise a support member extending between the end wall and the dirtcollection face. Optionally, the cyclone air inlet and the cyclone airoutlet may be provided at the first end of the cyclone chamber, thecyclone air outlet may comprise a vortex finder and porous memberpositioned between the cyclone chamber and an inlet of the vortexfinder, and the vortex finder and porous member may be spaced from thecyclone chamber face of the plate.

In any embodiment, the plate has a perimeter, the cyclone has agenerally axially extending sidewall and the annular gap may be providedbetween the perimeter of the plate and the sidewall.

In any embodiment, the cyclone has an axially extending sidewall and thesidewall has an end face and at least a portion of the end wall may facethe plate.

Optionally, the plate has a perimeter, the dirt collection region has asidewall and the annular gap may be provided between the perimeter ofthe plate and the sidewall.

DRAWINGS

The drawings included herewith are for illustrating various examples ofarticles, methods, and apparatus of the teaching of the presentspecification and are not intended to limit the scope of what is taughtin any way.

In the drawings:

FIG. 1 is a perspective view of a surface cleaning apparatus inaccordance with an embodiment;

FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. 1;

FIG. 3 is a cross-sectional view taken along line 2-2 in FIG. 1 of acyclone bin assembly of the surface cleaning apparatus of FIG. 1 whenremoved from the remainder of the surface cleaning apparatus;

FIG. 4 is a top perspective view of an arrester plate of the cyclone binassembly of FIG. 3;

FIG. 5 is a bottom perspective view of the arrester plate of FIG. 4;

FIG. 6 is the cross-sectional view of FIG. 3 with the cyclone binassembly in an open position;

FIG. 7 is a cross-sectional view of a cyclone bin assembly having anarrester plate in accordance with another embodiment;

FIG. 8 is a cross-sectional view of a cyclone bin assembly having anarrester plate in accordance with another embodiment;

FIG. 9 is a cross-sectional view taken along line 9-9 in FIG. 8;

FIG. 10 is a cross-sectional view taken along line 9-9 in FIG. 8 with anarrester plate in accordance with another embodiment;

FIG. 11 is a cross-sectional view a cyclone bin assembly with anarrester plate in accordance with another embodiment;

FIG. 12 is a top perspective view of the arrester plate of the cyclonebin assembly of FIG. 11;

FIG. 13 is a bottom perspective view of the arrester plate of thecyclone bin assembly of FIG. 11;

FIG. 14 is a cross-sectional view a cyclone bin assembly with anarrester plate in accordance with another embodiment;

FIG. 15 is a top perspective view of the arrester plate of the cyclonebin assembly of FIG. 14;

FIG. 16 is a bottom perspective view of the arrester plate of thecyclone bin assembly of FIG. 14;

FIG. 17 is a cross-sectional view a cyclone bin assembly with anarrester plate in accordance with another embodiment;

FIG. 18 is a top perspective view of the arrester plate of the cyclonebin assembly of FIG. 17; and,

FIG. 19 is a bottom perspective view of the arrester plate of thecyclone bin assembly of FIG. 17.

DESCRIPTION OF VARIOUS EMBODIMENTS

Various apparatuses, methods and compositions are described below toprovide an example of an embodiment of each claimed invention. Noembodiment described below limits any claimed invention and any claimedinvention may cover apparatuses and methods that differ from thosedescribed below. The claimed inventions are not limited to apparatuses,methods and compositions having all of the features of any oneapparatus, method or composition described below or to features commonto multiple or all of the apparatuses, methods or compositions describedbelow. It is possible that an apparatus, method or composition describedbelow is not an embodiment of any claimed invention. Any inventiondisclosed in an apparatus, method or composition described below that isnot claimed in this document may be the subject matter of anotherprotective instrument, for example, a continuing patent application, andthe applicant(s), inventor(s) and/or owner(s) do not intend to abandon,disclaim, or dedicate to the public any such invention by its disclosurein this document.

The terms “an embodiment,” “embodiment,” “embodiments,” “theembodiment,” “the embodiments,” “one or more embodiments,” “someembodiments,” “one embodiment”, and the like mean “one or more (but notall) embodiments of the present invention(s),” unless expresslyspecified otherwise.

The terms “including,” “comprising” and variations thereof mean“including but not limited to,” unless expressly specified otherwise. Alisting of items does not imply that any or all of the items aremutually exclusive, unless expressly specified otherwise. The terms “a,”“an” and “the” mean “one or more,” unless expressly specified otherwise.

As used herein and in the claims, two or more parts are said to be“coupled”, “connected”, “attached”, “joined”, “affixed”, or “fastened”where the parts are joined or operate together either directly orindirectly (i.e., through one or more intermediate parts), so long as alink occurs. As used herein and in the claims, two or more parts aresaid to be “directly coupled”, “directly connected”, “directlyattached”, “directly joined”, “directly affixed”, or “directly fastened”where the parts are connected in physical contact with each other. Asused herein, two or more parts are said to be “rigidly coupled”,“rigidly connected”, “rigidly attached”, “rigidly joined”, “rigidlyaffixed”, or “rigidly fastened” where the parts are coupled so as tomove as one while maintaining a constant orientation relative to eachother. None of the terms “coupled”, “connected”, “attached”, “joined”,“affixed”, and “fastened” distinguish the manner in which two or moreparts are joined together.

Furthermore, it will be appreciated that for simplicity and clarity ofillustration, where considered appropriate, reference numerals may berepeated among the figures to indicate corresponding or analogouselements. In addition, numerous specific details are set forth in orderto provide a thorough understanding of the example embodiments describedherein. However, it will be understood by those of ordinary skill in theart that the example embodiments described herein may be practicedwithout these specific details. In other instances, well-known methods,procedures, and components have not been described in detail so as notto obscure the example embodiments described herein. Also, thedescription is not to be considered as limiting the scope of the exampleembodiments described herein.

General Description of a Vacuum Cleaner

Referring to FIGS. 1-2, an exemplary embodiment of a surface cleaningapparatus is shown generally as 100. The following is a generaldiscussion of apparatus 100 which provides a basis for understandingseveral of the features which are discussed herein. As discussedsubsequently, each of the features may be used individually or in anyparticular combination or sub-combination in this or in otherembodiments disclosed herein.

Embodiments described herein include an improved cyclone assembly 116,and a surface cleaning apparatus 100 including the same. Surfacecleaning apparatus 100 may be any type of cyclonic surface cleaningapparatus, including for example a hand vacuum cleaner, a stick vacuumcleaner, a canister vacuum cleaner, and an upright vacuum cleaner.

In FIGS. 1-2, surface cleaning apparatus 100 is illustrated as a handvacuum cleaner, which may also be referred to also as a “handvac” or“hand-held vacuum cleaner”. As used herein, a hand vacuum cleaner is avacuum cleaner that can be operated to clean a surface generallyone-handedly. That is, the entire weight of the vacuum may be held bythe same one hand used to direct a dirty air inlet of the vacuum cleanerwith respect to a surface to be cleaned. For example, handle 104 anddirty air inlet 108 may be rigidly coupled to each other (directly orindirectly), such as being integrally formed or separately molded andthen non-removably secured together such as by an adhesive or welding,so as to move as one while maintaining a constant orientation relativeto each other. This is to be contrasted with canister and upright vacuumcleaners, whose weight is typically supported by a surface (e.g. afloor) during use, and when a canister vacuum cleaner is operated orwhen an upright vacuum cleaner is operated in a ‘lift-away’configuration, a second hand is typically required to direct the dirtyair inlet at the end of a flexible hose.

Still referring to FIGS. 1-2, surface cleaning apparatus 100 includes amain body 112 having an air treatment member 116 (which may bepermanently affixed to the main body or may be removable therefrom foremptying), a dirty air inlet 108, a clean air outlet 120, and an airflow path 124 extending between the dirty air inlet 108 and the cleanair outlet 120.

Surface cleaning apparatus 100 has a front end 128, a rear end 132, anupper end (also referred to as the top) 136, and a lower end (alsoreferred to as the bottom) 140. In the embodiment shown, dirty air inlet108 is at an upper portion of apparatus front end 128 and clean airoutlet 120 is at a rearward portion of apparatus 100 at apparatus rearend 132. It will be appreciated that dirty air inlet 108 and clean airoutlet 120 may be positioned in different locations of apparatus 100.

A suction motor 144 is provided to generate vacuum suction through airflow path 124, and is positioned within a motor housing 148. Suctionmotor 144 may be a fan-motor assembly including an electric motor andimpeller blade(s). In the illustrated embodiment, suction motor 144 ispositioned in the air flow path 124 downstream of air treatment member116. In this configuration, suction motor 144 may be referred to as a“clean air motor”. Alternatively, suction motor 144 may be positionedupstream of air treatment member 116, and referred to as a “dirty airmotor”.

Air treatment member 116 is configured to remove particles of dirt andother debris from the air flow. In the illustrated example, airtreatment member 116 includes a cyclone assembly (also referred to as a“cyclone bin assembly”) having a single cyclonic cleaning stage with asingle cyclone 152 and a dirt collection chamber 156 (also referred toas a “dirt collection region”, “dirt collection bin”, “dirt bin”, or“dirt chamber”). Cyclone 152 has a cyclone chamber 154, and dirtcollection chamber 156 may be external to the cyclone chamber 154 (i.e.dirt collection chamber 156 may have a discrete volume from that ofcyclone chamber 154). Cyclone 152 and dirt collection chamber 156 may beof any configuration suitable for separating dirt from an air stream andcollecting the separated dirt, respectively and may be in communicationby a dirt outlet of the cyclone chamber.

In alternate embodiments, air treatment member 116 may include a cycloneassembly having two or more cyclonic cleaning stages arranged in serieswith each other. Each cyclonic cleaning stage may include one or morecyclones arranged in parallel with each other and one or more dirtcollection chambers, of any suitable configuration. The dirt collectionchamber(s) may be external to the cyclone chambers of the cyclones.Alternatively, one or more (or all) of the dirt collection chamber(s)may be internal to one or more (or all) of the cyclone chambers. Forexample, the internal dirt collection chamber(s) may be configured as adirt collection area within the cyclone chamber.

Referring to FIG. 2, hand vacuum cleaner 100 may include a pre-motorfilter 160 provided in the air flow path 124 downstream of air treatmentmember 116 and upstream of suction motor 144. Pre-motor filter 160 maybe formed from any suitable physical, porous filter media. For example,pre-motor filter 160 may be one or more of a foam filter, felt filter,HEPA filter, or other physical filter media. In some embodiments,pre-motor filter 160 may include an electrostatic filter, or the like.As shown, pre-motor filter 160 may be located in a pre-motor filterhousing 164 that is external to the air treatment member 116.

In the illustrated embodiment, dirty air inlet 108 is the inlet end 168of an air inlet conduit 172. Optionally, inlet end 168 of air inletconduit 172 can be used as a nozzle to directly clean a surface.Alternatively, or in addition to functioning as a nozzle, air inletconduit 172 may be connected (e.g. directly connected) to the downstreamend of any suitable accessory tool such as a rigid air flow conduit(e.g., an above floor cleaning wand), a crevice tool, a mini brush, andthe like. As shown, dirty air inlet 108 may be positioned forward of airtreatment member 116, although this need not be the case.

In the embodiment of FIG. 2, the air treatment member comprises acyclone 152, the air treatment air inlet is a cyclone air inlet 184, andthe air treatment member air outlet is a cyclone air outlet 188.Accordingly, in operation, after activating suction motor 144, dirty airenters apparatus 100 through dirty air inlet 108 and is directed alongair inlet conduit 172 to the cyclone air inlet 184. As shown, cycloneair inlet 184 may direct the dirty air flow to enter cyclone chamber 154in a tangential direction so as to promote cyclonic action. Dirtparticles and other debris may be disentrained (i.e. separated) from thedirty air flow as the dirty air flow travels from cyclone air inlet 184to cyclone air outlet 188. The disentrained dirt particles and debrismay discharge from cyclone chamber 154 through a dirt outlet 190 intodirt collection chamber 156 external to the cyclone chamber 154, wherethe dirt particles and debris may collect until dirt collection chamber156 is emptied.

Air exiting cyclone chamber 154 may pass through an outlet passage 192located upstream of cyclone air outlet 188. Cyclone chamber outletpassage 192, may also act as a vortex finder to promote cyclonic flowwithin cyclone chamber 154. In some embodiments, cyclone outlet passage192 may include a porous member such as a screen or shroud 196 (e.g. afine mesh screen) in the air flow path 124 (e.g., positioned between thecyclone chamber and an inlet of the vortex finder) to remove large dirtparticles and debris, such as hair, remaining in the exiting air flow.The vortex finder and porous member may be spaced from the cyclonechamber face of plate 216. It will be appreciated that, in someembodiments, only a screen may be provided. Alternately a vortex findermay be provided without a screen or the like.

From cyclone air outlet 188, the air flow may be directed into pre-motorfilter housing 164 at an upstream side 204 of pre-motor filter 160. Theair flow may pass through pre-motor filter 160 to pre-motor filterdownstream side 208, and then exit through pre-motor filter chamber airoutlet 212 into motor housing 148. At motor housing 148, the clean airflow may be drawn into suction motor 144 and then discharged fromapparatus 100 through clean air outlet 120.

Axially Stepped Arrester

The following is a description of a dirt arrester plate (also referredto as a “dirt arrester”, “arrester plate”, or simply “plate”) thatseparates the cyclone chamber from the dirt collection chamber that maybe used in any cyclone design. In accordance with this feature, the dirtcollection chamber is external to the cyclone chamber and the dirtoutlet from the cyclone chamber comprises or consists of a gap betweenthe arrester plate and the cyclone chamber sidewall. In accordance withthis design, the arrester plate has an ‘axial step’, in which a portionof the arrester plate is axially recessed to create an axially recessedstep. The axial step may create a relatively larger dirt outlet gapbetween the cyclone chamber sidewall and the stepped portion of thearrester plate periphery, which can allow larger debris to pass throughthe dirt outlet.

Without being limited by theory, as compared with an entirely planararrester plate having a generally uniformly sized dirt outlet gap, theaxially stepped arrester design may provide greater separationefficiency (i.e. percentage of dirt particles of a dirty air flowseparated from the air flow and retained in the dirt collection chamber)by permitting larger dirt particles to exit the cyclone chamber therebyreducing the likelihood that larger dirt particles in the cyclonechamber may produce eddy currents or otherwise interfere with the flowpattern in a cyclone chamber. Thus, the axially stepped arrester designmay allow the dirt collection chamber to admit large dirt particles(e.g. stones, dry foods, etc.) while providing a high separationefficiency.

Reference is now made to FIGS. 3-5. As shown, cyclone bin assembly 116includes an arrester plate 216 that separates cyclone chamber 154 fromdirt collection chamber 156. Arrester plate 216 also cooperates withcyclone 152 to define dirt outlet 190 from cyclone chamber 154 into dirtcollection chamber 156.

Arrester plate 216 may define at least part of an end wall for one orboth of cyclone 152 and dirt collection chamber 156. As shown, arresterplate 216 may have a cyclone chamber face 220 that borders cyclonechamber 154, and an opposite dirt chamber face 224 that borders dirtcollection chamber 156. Cyclone chamber face 220 may face towards aninterior volume of cyclone chamber 154. Similarly, dirt chamber face 224may face towards an interior volume of dirt collection chamber 156.

Cyclone 152 has a first end 228 having a first end wall 232, a secondend 236 axially spaced apart from first end 228, and a cyclone chambersidewall 240 positioned between the first and second ends 228 and 236.Cyclone 152 also has a central longitudinal axis 242 (also referred toas a “cyclone axis”) that extends from the first end 228 to the secondend 236. In the example shown, cyclone second end 236 may be defined atleast in part by cyclone chamber face 220 of arrester plate 216. In someembodiments, at least a portion of cyclone chamber face 220 faces (i.e.has a surface normal pointed towards) cyclone first end 228. It will beappreciated that, if plate 216 is spaced from sidewall 240, thensidewall 240 will not extend to plate 216. In some embodiments, aportion of plate 216 may abut portions of sidewall 240 while anotherportion, e.g., the stepped down portion, may be spaced from sidewall 240to define part or all of the dirt outlet.

Still referring to FIGS. 3-5, cyclone outlet passage 192 may define avortex finder that promotes cyclonic flow within cyclone chamber 154. Asshown, cyclone outlet passage 192 may extend from a first end 244 atcyclone first end 228, to a second end 248 within cyclone chamber 154.Cyclone outlet passage 192 has one or more inlet openings 252 that admitair exiting cyclone chamber 154 to enter cyclone outlet passage 192towards cyclone air outlet 188. Cyclone outlet passage opening(s) 252may be overlaid with a porous member 254 (e.g. a fine mesh screen),which may remove large dirt and debris from the air flow entering thecyclone outlet passage 192. As shown, cyclone outlet passage 192 andporous member 254 may be spaced (e.g. axially) from cyclone chamber face220 of arrester plate 216. Cyclone outlet passage 192 may be intersectedby cyclone axis 242. As shown, cyclone outlet passage 192 may have acentral longitudinal axis 256 that is parallel to cyclone axis 242 (e.g.collinear to cyclone axis 242, or spaced apart from cyclone axis 242).

It will be appreciated that any cyclone air outlet may be used and thatthe cyclone air outlet may be at various locations as is known in theart. Similarly, it will be appreciated that any cyclone air inlet 184may be used and that the cyclone air inlet may be at various locationsas is known in the art.

Dirt collection chamber 154 has a first end 260, a second end 264axially spaced apart from first end 260, and a sidewall 268 that extendsbetween the first and second ends 260 and 264. Dirt collection chamber154 has a longitudinal axis 272 (also referred to as a “dirt chamberaxis”). Dirt chamber axis 272 may be parallel to cyclone axis 242 (e.g.collinear to cyclone axis 242, or transversely spaced apart from cycloneaxis 242). Dirt chamber first end 260 may be defined at least in part bydirt chamber face 224 of arrester plate 216. Dirt chamber second end 264may include a second end wall 276. In some embodiments, at least aportion of dirt chamber face 224 faces (i.e. has a surface normallypointed towards) dirt chamber second end 264.

As used herein, the term “axial” and “axially” mean “in a directionparallel to the respective longitudinal axis”, such as for examplecyclone axis 242 or dirt chamber axis 272. For example, dirt chamberface 224 may be described as being axially spaced apart from cyclonechamber face 220 in that dirt chamber face 224 is spaced from cyclonechamber face 220 in a direction parallel to or along the cyclone axis242.

Referring to FIGS. 8-9, cyclone dirt outlet 190 may extend around all ofarrester plate periphery 288. As shown, every point on arrester plateperiphery 288 may have a (non-zero) dirt outlet gap length 292 tocyclone chamber sidewall 240. In this way, dirt outlet 190 may form acontinuous annular gap. This helps to mitigate the development ofblockages caused by an accumulation of debris at locations where thereis no dirt outlet 190, e.g. because the dirt outlet 190 is obstructed.In other embodiments, arrester plate 216 may about part of sidewall 240.

Referring to FIGS. 3 and 6, arrester plate 216 may be movable between aclosed position (FIG. 3) and an open position (FIG. 6). In the closedposition, arrester plate 216 may act to separate cyclone chamber 154from dirt collection chamber 156. If plate 216 contacts part of sidewall240, then arrester plate 216 may at least partially close cyclone secondend 236 when in the closed position. Alternately, as exemplified inFIGS. 3 and 8-10, plate 216 may be spaced from all of sidewall 240 whenin the closed position. In the open position, arrester plate 216 may bepositioned to provide user access to cyclone chamber 154 (e.g. forcleaning). For example, arrester plate 216 may close less of or none ofcyclone second end 236 when in the open position as compared to theclosed position.

As shown, arrester plate 216 may be connected to an openable end wall276 of dirt collection chamber 156. Arrester plate 216 may move with endwall 276 so that when end wall 276 is opened, arrester plate 216 isdisplaced from (i.e. moved away from) cyclone second end 236. Thisallows cyclone chamber 154 and dirt collection chamber 156 to be openedand emptied concurrently by moving end wall 276 from its closed position(FIG. 3) to its open position (FIG. 6). Alternately, plate 216 may bepivotally mounted to sidewall 240, to a sidewall of the dirt chamber,

In some embodiments, plate 216 may not be openable, or it may beopenable separately from the dirt chamber. For example, plate 216 may bepivotally mounted to sidewall 240 or to a sidewall of the dirt chamberand may have its own releasable lock. Accordingly, plate 216 may remainin position when end wall 276 is opened and may be separately openable.

Dirt chamber end wall 276 may be openable in any manner that allowsaccess to empty dirt collection chamber 156. For example, dirt chamberend wall 276 may be pivotally openable as shown, or removable from dirtcollection chamber 156. In the illustrated example, dirt chamber endwall 276 is rotatably connected to dirt collection chamber sidewall 268by a hinge 280, and releasably held in the closed position (FIG. 3) by alatch 284.

Arrester plate 216 may be connected to dirt chamber end wall 276 in anymanner that allows arrester plate 216 to open concurrently as dirtchamber end wall 276 is opened. In the illustrated example, arresterplate 216 is connected to dirt chamber end wall 276 by a rigidly mountedsupport member 286. Accordingly, support member 286 may be a post thatrigidly connects arrester plate 216 to dirt chamber end wall 276,whereby arrester plate 216 and dirt chamber end wall 276 move as one. Insome embodiments, support member 286 may be moveable (pivotally) mountedwith respect to end wall 276 and/or plate 216 may be moveable(pivotally) mounted with respect to support 268. As shown, supportmember 286 may extend from dirt chamber face 224 of arrester plate 216to dirt chamber end wall 276. In this example, at least a portion ofdirt chamber end wall 276 faces (i.e. has a surface normal pointedtowards) arrester plate 216 (e.g. towards dirt chamber face 224).

Returning to FIGS. 3-5, cyclone dirt outlet 190 may be formed by a gapbetween cyclone chamber sidewall 240 and the arrester plate 216). Dirtthat is disentrained (i.e. separated) from the airflow circulatingthrough cyclone chamber 154 (e.g. by cyclonic action within cyclonechamber 154) may exit cyclone chamber 154 through dirt outlet 190 intodirt collection chamber 156. The maximum size of a dirt particle thatcan exit through dirt outlet 190 is defined by a gap length 292. Gaplength 292 is the shortest distance between a given point on arresterplate 216 and cyclone chamber sidewall 240.

There may be a uniform gap length 292 at every point on arrester plateperiphery 288, or gap length 292 may vary along arrester plate periphery288.

As exemplified in FIG. 3, plate 216 may have a diameter similar to thediameter of cyclone chamber 154 and the cyclone axis may intersect thecentre of arrester plate 216. Accordingly the arrester plate periphery288 (also referred to as “arrester plate perimeter”) may underlie thesidewall 240 (i.e., a projection of sidewall 240 may intersect thearrester plate periphery 288) such that arrester plate periphery 288underlies a free end 296 of cyclone chamber sidewall 240. Accordingly,as exemplified in FIG. 3, dirt outlet 190 is defined by a gap length292, which is solely axial. That is, the shortest distance between everypoint on arrester plate periphery 288 and cyclone chamber sidewall 240is in a direction parallel to cyclone axis 242.

It will be appreciated that the cross sectional area of plate 216 andthe outlet end of the cyclone chamber 154 may vary (e.g., plate 216 mayhave a diameter that is smaller than or larger than the diameter ofcyclone chamber 154). The arrester plate may be coplanar with free end296 of cyclone chamber sidewall 240 (see for example FIG. 7) or is maybe axially spaced therefrom (See for example FIG. 8).

FIG. 7 shows an example in which arrester plate 216 has a diameter thatis smaller than the diameter of cyclone chamber 154 so that at least aportion of dirt outlet 190 is defined by gap lengths 292 that are solelyradial. That is, the shortest distance between at least a portion 304 ofarrester plate periphery 288 and cyclone chamber sidewall 240 is in adirection that is transverse (e.g. perpendicular) to cyclone axis 242.As shown, at least portion 304 of arrester plate periphery 288 has thesame axial position as a portion of cyclone chamber sidewall 240.

FIG. 8 shows an example in which all of dirt outlet 190 is defined bygap lengths 292 that include radial and axial components. That is, theshortest distance between at least a portion 304 of arrester plateperiphery 288 and cyclone chamber sidewall 240 is in a direction that isat a non-zero and non-perpendicular angle (i.e. non-parallel andnon-orthogonal) to cyclone axis 242.

Different points on arrester plate periphery 288 may have different dirtoutlet gap lengths 292. FIG. 9 shows an example in which arrester plate216 is off-centered relative to cyclone axis 242 whereby radial gaplength 292 is greater at some points along arrester plate periphery 288than others (e.g. compare gap length 292 ₁ to gap length 292 ₂).Alternatively, or in addition, arrester plate periphery 288 may have anaxial shape (i.e. the shape of a projection of arrester plate periphery288 in a direction parallel to cyclone axis 242) that differs from theaxial shape of cyclone chamber sidewall 240 where cyclone chambersidewall 240 is nearest to arrester plate periphery 288 (e.g. atriangular arrester plate periphery 288 and circular cyclone chambersidewall 240). This too may produce a variable gap length 292 aroundarrester plate periphery 288.

Returning to FIGS. 3-5, the illustrated arrester plate 216 is shownincluding an upper plateau and a peripheral step on one side. Theperipheral step can provide an enlarged dirt outlet gap length acrossonly the stepped portion of the dirt arrester periphery. An advantage ofthis design is that the enlarged dirt outlet gap provides clearance forlarge dirt particles to pass through the dirt outlet into the dirtcollection chamber while optionally maintaining a smaller gap for theremainder of the perimeter of the arrester plate (if the remainder ofthe arrester plate is spaced from sidewall 240). As compared with a dirtarrester that has a comparably large gap length about the entirearrester plate periphery, the illustrated axially stepped design maymitigate re-entry of dirt from the dirt collection chamber into thecyclone chamber through the dirt outlet because much of the dirt outletretains a relatively smaller gap length. In laboratory testing, theaxially stepped design produced greater dirt separation efficiency ascompared with a uniformly planar arrester plate, all else being equal.

As shown, arrester plate 216 includes a first portion 308 and a secondportion 312. The first and second portions 308 and 312 are axiallyspaced apart and joined together by a transition portion 316 positionedbetween the first and second portions 308 and 312. In the illustratedexample, transition portion 316 extends from first portion 308 to secondportion 312. First, second, and transition portions 308, 312, and 316may be integrally formed as shown, or discretely formed and rigidlyconnected together. At least the first and second portions 308 and 312each include a portion of arrester plate periphery 288. In theillustrated example, each of the first, second, and transition portions308, 312, and 316 include a portion of arrester plate periphery 288.

Each of first, second, and transition portions 308, 312, and 316includes a cyclone chamber face 320 ₁, 320 ₂, and 320 ₃ respectively.Cyclone chamber faces 320 border the inner volume of cyclone chamber154. As shown, second portion cyclone chamber face 320 ₂ may be axiallyspaced (i.e. in a direction parallel to cyclone axis 242) apart fromfirst portion cyclone chamber face 320 ₁ in a direction away fromcyclone first end 228. Thus, arrester plate second portion 312 forms anaxial step from the arrester plate first portion 308. As shown, theaxial separation between arrester plate first and second portions 308and 312 may provide arrester plate periphery 288 with a greater dirtoutlet gap length 292 at arrester plate second portion 312 than atarrester plate first portion 308. This allows larger particles to passthrough dirt outlet 190 at arrester plate second portion 312, whilemaintaining a smaller gap at arrester plate first portion 308 tomitigate re-entry of dirt particles from dirt collection chamber 156into cyclone chamber 154.

As shown, cyclone chamber faces 320 ₁ and 320 ₂ of arrester plate firstand second portions 308 and 312 may face towards cyclone first end 228(e.g. towards cyclone first end wall 232). In the illustrated example,cyclone chamber faces 320 ₁ and 320 ₂ are substantially planar andperpendicular to cyclone axis 242. In other embodiments, one or both ofcyclone chamber faces 320 ₁ and 320 ₂ may be non-planar. Alternativelyor in addition, one or both of cyclone chamber faces 320 ₁ and 320 ₂ maybe non-perpendicular to cyclone axis 242.

Axial separation between cyclone chamber faces 320 ₁ and 320 ₂ may bedescribed by their distances from a reference plane 324 (also referredto as a “transverse plane”), which is perpendicular to cyclone axis 242and intersects the cyclone, such as at cyclone first end 228. As shown,axial distance 322 ₂ from second portion cyclone chamber face 320 ₂ toreference plane 324 is greater than axial distance 322 ₁ from firstportion cyclone chamber face 320 ₁ to reference plane 324.

Transition cyclone chamber face 320 ₃ may extend at a non-zero angle tofirst and second portion cyclone chamber faces 320 ₁ and 320 ₂. Asshown, transition cyclone chamber face 320 ₃ may extend substantiallyaxially (e.g. substantially parallel to cyclone axis 242). In theexample shown, transition cyclone chamber face 320 ₃ extendsperpendicular to first and second portion cyclone chamber faces 320 ₁and 320 ₂. As shown, transition cyclone chamber face 320 ₃ may besubstantially planar.

In some embodiments, transition cyclone chamber face 320 ₃ may benon-perpendicular to cyclone axis 242. For example, it may extend at anacute angle to each of first and second portion cyclone chamber faces320 ₁ and 320 ₂. Alternately, or in addition, transition cyclone chamberface 320 ₃ may be non-planar; for example, it may curve from first andsecond portion cyclone chamber face 320 ₁ to second portion cyclonechamber face 320 ₂. For example, transition cyclone chamber face 320 ₃may be concave or convex.

Arrester plate second portion 312 may be smaller in size (e.g., crosssectional area in a plane parallel to reference plane 324) than arresterplate first portion 308. An advantage of this design is that it providesarrester plate with an enlarged dirt outlet gap length 292 across lessthan half of dirt outlet 190. For example, the area of an axialprojection of arrester plate second portion 312 may be smaller (e.g.,less than 50%, less than 40%, less than 30%, less than 20% or less than10%) than the area of an axial projection of arrester plate firstportion 308. In the illustrated example, the area of an axial projectionof arrester plate second portion 312 is less than one half of the areaof an axial projection of arrester plate first portion 308. In addition,arrester plate second portion 312 may include less of arrester plateperiphery 288 than arrester plate first portion 308 (e.g., less than50%, less than 40%, less than 30%, less than 20% or less than 10%). Inthe illustrated example, arrester plate second portion 312 includes lessthan one quarter of arrester plate periphery 288.

Arrester plate second portion 312 may be laterally offset (i.e. in adirection perpendicular to cyclone axis 242) from cyclone axis 242. Asshown, arrester plate second portion 312 is axially spaced from arresterplate first portion 308 along an axial line 326 that is parallel andlaterally spaced from cyclone axis 242.

Transition cyclone chamber face 320 ₃ may meet first and second portioncyclone chamber faces 320 ₁ and 320 ₂ at first and seconddiscontinuities 328 ₁ and 328 ₂ respectively. As shown, transitioncyclone chamber face 320 ₃ extends between first and seconddiscontinuities 328 ₁ and 328 ₂. First discontinuity 328 ₁ may bepositioned between first portion cyclone chamber face 320 ₁ andtransition portion cyclone chamber face 320 ₃, and second discontinuitymay be positioned between second portion cyclone chamber face 320 ₂ andtransition portion cyclone chamber face 320 ₃.

As used herein, a “discontinuity” is a macro-scale deviation ordisruption of a surface pattern or shape pattern. For example, firstdiscontinuity 328 ₁ is shown as a 90 degree bend that is a deviationfrom the planar surface of first portion cyclone chamber face 320 ₁, andsecond discontinuity is shown as a 90 degree bend that is a deviation ofthe planar surface of second portion cyclone chamber face 320 ₂. Minordeviations (e.g. seams and clearance gaps between otherwise continuousportions), and micro deviations (e.g. elements of surface texture) arenot considered herein to be discontinuities. It will be appreciatedthat, instead of a 90 degree bend, the discontinuities may be rounded.

It will be appreciated that arrester plate 216 may have a perimeterwithout any angles or other discontinuities. Arrester plate periphery288 may therefore have a continuous axial shape (i.e. the shape of aprojection of arrester plate periphery 288 in a direction parallel tocyclone axis 242) that is smooth. Accordingly, as shown in plan view inFIG. 9, arrester plate 216 is circular.

It will be appreciated that arrester plate may be of any other shapesuch as elliptical or polygonal (e.g., hexagonal, square, triangle orthe like). For example, as exemplified in FIG. 10, an arrester plateperiphery 288 may have a discontinuous axial shape. In the exampleshown, arrester plate periphery 288 has first and second portions 332and 336 connected by two discontinuities 340. Discontinuities 340provide deviations from the regular (e.g. circular) shape of peripheryfirst portion 332, and the regular (e.g. linear) shape of peripherysecond portion 336. In this example, discontinuities 340 are corners(also referred to as junctures) between first and second portions 332and 336.

It will be appreciated that arrester plate 216 may have an irregularperimeter. For example, the arrester plate may have a shape wherein partof the plate has been truncated to increase the size of the dirt outletgap. The truncated portion may be any portion of the plate and may beprovided on the second portion. This feature may be used with any platethat has a smooth perimeter or which has a perimeter withdiscontinuities.

For example, as exemplified in FIG. 10, first and second discontinuities340 ₁ and 340 ₂ may be provided on arrester plate second portion 312.For example, second portion 336 of arrester plate periphery 288 mayborder at least a portion of arrester plate second portion 312. Ascompared to arrester plate 216 were the axial shape of periphery firstportion 332 continuous around the entire arrester plate periphery 288(e.g. fully circular), a plate segment 344 has been removed whereperiphery second portion 336 truncates the axial shape of peripheryfirst portion 332. As shown, periphery second portion 336 may be formedas a cord (e.g. linear crop) to the circular axial shape of peripheryfirst portion 332. The removal of plate segment 344 may further enlargedirt outlet gap lengths 292 at arrester plate second portion 312. Thisallows arrester plate 216 to allow even larger particles to pass throughthe portion of dirt outlet 190 located between periphery second portion336 and cyclone sidewall 240, as compared to the same arrester plate 216with plate segment 344 intact.

It will be appreciated that an arrester plate 216 with an axial step cancreate a concave (also referred to as ‘hollow’) step volume behind theaxial face of the step. Depending on the manner in which the associatedcyclone and dirt collection chambers are emptied, fibrous debris (e.g.hair) may snag or accumulate in the step volume when emptying thesurface cleaning apparatus. Alternately, a hollow shape of the dirtchamber facing side of plate 216 may create eddy currents or otherwiseinterfere with dirt settling in the dirt collection chamber. Therefore,in some embodiments the step volume is closed by the dirt chamber faceof the arrester plate. Closing the hollow step volume may be used withany axially stepped arrester described herein.

It will be appreciated that the closure portion may underlie or traverseonly the transition portion, (e.g., if the transition portion extends atan angle to reference plane 324). Alternately the closure portion myunderlie both the transition portion and one or both of the first andsecond portions. As exemplified in FIGS. 11-19, the closure portionunderlies both the transition portion and the first portion. Anadvantage of this design is that the axial thickness of the secondportion is not increased. It will be appreciated that the more of thefirst portion that the closure portion underlies, the more gradual theangle of the closure portion may be.

Referring to FIGS. 4-5, an example arrester plate 216 is shown includingan open step volume 348. Step volume 348 is a hollow volume behindtransition portion dirt chamber face 364 ₃. As shown, step volume 348 isbordered by transition portion 316 to one side and by first portion 308above.

FIGS. 11-13 exemplify an embodiment of arrester plate 216 in which stepvolume 348 is closed by a closure portion 352 of dirt chamber face 224.As shown, closure portion 352 may be opposed to transition portioncyclone chamber face 320 ₃ and to at least a portion of first portioncyclone chamber face 320 ₁. By closing step volume 348, a smoother dirtchamber face of plate 216 is provided which may reduce eddy currents inthe dirt collection chamber and facilitate dirt settling in the dirtcollection chamber and not being reintrained into the cyclone chamber.

Closure portion 352 may have any configuration suitable to close stepvolume 348. In some embodiments, closure portion 352 may be free ofconcavities (e.g. entirely planar as shown, entirely convex, or includeboth planar and convex portions). In the illustrated example, closureportion 352 extends from a first end 356 proximate dirt chamber face 364₂ of second portion 312 towards or across cyclone axis 242 to second end360 within dirt chamber face 364 ₁ of first portion 308.

FIGS. 11-13 exemplify an example in which closure portion second end 360is proximate cyclone axis 242. FIGS. 14-16 exemplify an example ofarrester plate 216 in which cyclone axis 288 is located between closureportion first and second ends 356 and 360. FIGS. 17-19 exemplify anotherexample of arrester plate 216 in which cyclone axis 288 is locatedbetween closure first and second ends 356 and 360.

Closure portion 352 may extend transverse (i.e. non-parallel) to cycloneaxis 242. For example, FIGS. 11-13 and 14-16 show examples of arresterplate 216 in which closure portion 352 is neither parallel norperpendicular to cyclone axis 242. As shown, closure portion first end356 may be axially and laterally spaced apart from closure portionsecond end 360. In the illustrated example, closure portion first end356 is axially spaced from closure portion second end 360 away fromcyclone chamber first end 228. FIGS. 17-19 show an example of arresterplate 216 in which closure portion first end 356 is axially aligned andlaterally spaced apart from closure portion second end 360.

Referring again to FIGS. 11-13, closure portion 352 may be oriented sothat it diverges from cyclone chamber face 320 ₃ of transition portion316 in a direction away from arrester plate second portion 312. Asshown, closure portion second end 360 may be spaced farther from cyclonechamber face 320 ₃ of transition portion 316 than closure portion firstend 356.

Dirt chamber face 224 may have one or more discontinuities. For example,FIGS. 11-13 and 14-16 illustrate arrester plates 216 having a dirtchamber face 224 with a discontinuity 368 at the juncture of closureportion 352 and dirt chamber face 364 ₂ of second portion 312. Thediscontinuity is preferably rounded so as to avoid a sharp angle. Inother embodiments, dirt chamber face 224 may be entirely continuous. Forexample, FIGS. 17-19 show an arrester plate 216 having a dirt chamberface 224 that is entirely planar. In the illustrated example, dirtchamber face 224 is perpendicular to cyclone axis 242. In otherembodiments, dirt chamber face 224 may be oriented non-perpendicular andnon-parallel to cyclone axis 242.

Plate first portion 308 may have an axial thickness 372 ₁ greater thanaxial thickness 372 ₂ of plate second portion 312. FIGS. 17-19 show anexample arrester plate 216 having a plate first portion 308 with auniform thickness 372 ₁ that is greater than thickness 372 ₂ of platesecond portion 312. FIGS. 11-13 and 14-16 show example arrester plates216 having a plate first portion 308 with a thickness 372 ₁ thatincreases towards transition portion 316. As shown, plate thickness 372₁ may increase between closure portion first and second ends 356 and 360towards first end 356.

While the above description provides examples of the embodiments, itwill be appreciated that some features and/or functions of the describedembodiments are susceptible to modification without departing from thespirit and principles of operation of the described embodiments.Accordingly, what has been described above has been intended to beillustrative of the invention and non-limiting and it will be understoodby persons skilled in the art that other variants and modifications maybe made without departing from the scope of the invention as defined inthe claims appended hereto. The scope of the claims should not belimited by the preferred embodiments and examples, but should be giventhe broadest interpretation consistent with the description as a whole.

The invention claimed is:
 1. A vacuum cleaner comprising: (a) an airflow path extending from a dirty air inlet to a clean air outlet; (b) acyclone assembly comprising a cyclone provided in the air flow path anda dirt collection region, the cyclone comprising a cyclone chamber, acyclone air inlet, a cyclone air outlet, a dirt outlet, a centrallongitudinally extending axis, the cyclone chamber having first andsecond axially opposed ends, the dirt collection region is external tothe cyclone chamber; (c) a suction motor positioned in the air flowpath; and, (d) a plate positioned at the second end of the cyclonechamber, the plate having a cyclone chamber face facing the cyclonechamber, the cyclone chamber face having first and second portions,wherein the first portion of the cyclone chamber face and the secondportion of the cyclone chamber face are different axial distances from atransverse plane that extends through the cyclone chamber and that isperpendicular to the central longitudinally extending axis of thecyclone, wherein the plate has a perimeter and the perimeter of theplate is spaced from a sidewall of the cyclone assembly, and wherein anannular gap between the plate and the cyclone extends around all of theplate and defines the dirt outlet of the cyclone chamber.
 2. The vacuumcleaner of claim 1 wherein the annular gap has a radial distance betweenthe plate and the cyclone and the radial distance is constant.
 3. Thevacuum cleaner of claim 1 wherein the annular gap has a radial distancebetween the plate and the cyclone and the radial distance varies atdifferent locations around the plate.
 4. The vacuum cleaner of claim 1wherein the perimeter extends generally continuously.
 5. The vacuumcleaner of claim 1 wherein the perimeter has two discontinuities.
 6. Thevacuum cleaner of claim 1 wherein the plate has a segment removed. 7.The vacuum cleaner of claim 6 wherein the annular gap has a radialdistance between the plate and the cyclone, the radial distance variesat different locations around the plate and the radial distance isincreased at a location of the plate from which the segment has beenremoved.
 8. The vacuum cleaner of claim 7 wherein the second portion isa greater axial distance from the transverse plane than the firstportion and the location of the plate from which the segment has beenremoved is the second portion.
 9. The vacuum cleaner of claim 1 whereinthe second portion is a greater axial distance from the transverse planethan the first portion and the second portion has a segment removed. 10.The vacuum cleaner of claim 9 wherein the annular gap has a radialdistance between the plate and the cyclone and the radial distance isincreased at a location of removal of the segment.
 11. The vacuumcleaner of claim 1 wherein the plate is positioned between the cyclonechamber and the dirt collection region, the plate has a dirt collectionface facing the dirt collection region.
 12. The vacuum cleaner of claim1 wherein the cyclone air inlet and the cyclone air outlet are providedat the first end of the cyclone chamber, the cyclone air outletcomprises a vortex finder and porous member positioned between thecyclone chamber and an inlet of the vortex finder, and the vortex finderand porous member are spaced from the cyclone chamber face of the plate.13. The vacuum cleaner of claim 1 wherein the plate is moveably mountedbetween a closed position, in which the plate is positioned foroperation of the cyclone and an open position wherein the plate is movedto provide access to the cyclone chamber.
 14. The vacuum cleaner ofclaim 13 wherein the dirt collection region has an end wall facing theplate and the end wall is openable.
 15. The vacuum cleaner of claim 14wherein the plate is supported by the end wall and is moveable with theend wall.
 16. The vacuum cleaner of claim 15 wherein the plate has adirt collection face facing the dirt collection region and the vacuumcleaner further comprises a support member extending between the endwall and the dirt collection face.
 17. The vacuum cleaner of claim 16wherein the cyclone air inlet and the cyclone air outlet are provided atthe first end of the cyclone chamber, the cyclone air outlet comprises avortex finder and porous member positioned between the cyclone chamberand an inlet of the vortex finder, and the vortex finder and porousmember are spaced from the cyclone chamber face of the plate.
 18. Thevacuum cleaner of claim 1 wherein the cyclone has a generally axiallyextending sidewall and the annular gap is provided between the perimeterof the plate and the sidewall.
 19. The vacuum cleaner of claim 1 whereinthe cyclone has an axially extending sidewall and the sidewall has anend face and at least a portion of the end wall faces the plate.
 20. Thevacuum cleaner of claim 19 wherein the dirt collection region has asidewall and the annular gap is provided between the perimeter of theplate and the sidewall.